Tacky allergen trap and filter medium, and method for containing allergens

ABSTRACT

An allergen trap is provided. The allergen trap includes a woven or nonwoven substrate having at least one strata. The trap is impregnated with or otherwise treated with a tacky adhesive by which allergens may be trapped. An example of an allergen is a dust mite. The tacky adhesive, in turn, may be treated with a miticide or activated carbon.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 12/643,717, filed Dec. 21, 2009; which is a continuation applicationof U.S. application Ser. No. 11/624,580, filed Jan. 18, 2007, whichissued as U.S. Pat. No. 7,727,915 on Jun. 1, 2010; which claims priorityunder 35 U.S.C. §119 from U.S. Provisional Application Ser. No.60/760,323, filed Jan. 18, 2006, and from U.S. Provisional ApplicationSer. No. 60/880,873, filed Jan. 16, 2007. The disclosures of thesereferenced applications are incorporated herein by reference in theirentireties.

FIELD OF THE INVENTION

The present invention relates to nonwoven materials. The inventionfurther relates to nonwoven substrates which provide one or moreallergen-retaining layers for trapping dust mites or other allergensinto and out of cushioning material. The invention also relates to aprocess for the manufacture of a filtration medium employing a nonwovensubstrate having at least one stratum bearing a tacky adhesive fortrapping allergens.

BACKGROUND OF THE INVENTION

Some humans experience sensitivities or allergic reactions to airbornemicro-particles. Such particles may be feline-spawned allergens such ascat dander. Other particles may be, for example, dust mites or the fecesor exoskeleton of dust mites. Dust mites are of particular concern dueto their propensity to propagate in cushioning materials such asmattresses, pillows and furniture cushions.

Dust mites are arachnids, and belong to the subclass acari. There aretwo common dust mites: the American house dust mite (Dermatophagoidesfarinae) and the European house dust mite (D. pteronyssinus). Dust mitesfeed on the dead skin that falls off the bodies of humans and animalsand on other organic material found where they live. They are extremelysmall, being only about 100-1000μ. Moreover, dust mites are virtuallytransparent and can be difficult to see without sophisticatedmicroscopy. Dust mite feces and exoskeletal particles are even smaller,and can be 10 to 20 microns.

It is now generally accepted that dust mites, dust mite feces and othermicroscopic allergens are a significant cause of many asthmatic andallergic reactions in the home. Such micro-particles may be inhaled by ahuman coming into contact with infested pillows or bedding. To reduceexposure to dust mite allergens, various suggestions have been made forcovering bedding in covers which act as a barrier to the passage ofallergens. In this respect, it is known to cover allergen-bearingarticles such as mattresses and cushions with a cover which serves as adust-mite barrier. Such coverings define plastic materials or finelywoven materials having openings of a size sufficiently small to inhibitthe passage of dust mites there through. For instance, U.S. Pat. No.5,050,256 discloses an allergen-barrier bedding cover made from a coatedfabric. The fabric is said to have a pore size of less than 10 micronsto prevent the passage of dust mites. The fabric is sewn to form thecover and the seams are sealed with an additional coating ofpolyurethane.

U.S. Pat. No. 5,321,861 discloses a protective cover for upholstered orpadded articles. The cover is made from a microporous ultrafiltermaterial having pores of less than 0.5 microns. To eliminate possibleleakage of allergens through the seams or zipper closure, the cover isconstructed using high frequency welding, and the zipper is covered byan adhesive tape.

U.S. Pat. No. 6,017,601 entitled Allergen-Barrier Cover presents a coverfabricated from a multi-layered fabric material. The material definesmeltblown and spunbonded layers made from polypropylene which permitsthe passage of air but is said to be impermeable to the passage of waterand of dust mites.

It is noted that the solutions offered from the above patents primarilyattempt to trap dust mites within an allergen-carrying article, but donot seek to eliminate them. Further, the solutions do not enhance thecushioning or comfort of the user on the allergen-carrying article aswould be offered by a nonwoven-based article.

Conventional miticides (or acaricides) based upon organophosphatecompounds have been used for the extermination of mites. Such compoundsare typically diluted in an aqueous spray. However, such compounds,while effective in eradicating mite infestations outdoors such as infarms, are not feasible for indoor use. In this respect, such acaricidesare toxic to humans, and the extermination of mites by spraying ofmiticide chemicals has the side-effect of polluting the inhabitedenvironment while also posing a toxicity risk for humans, particularlychildren and infants, as well as cats. Further, organophosphateacaricides cannot be used on beddings and, therefore the mites are leftundisturbed in their main living site.

It is proposed here to provide a nonwoven structure having a tackycharacteristic as a trap or filtering medium for allergens. In addition,a method for trapping allergens using a tacky material around anallergen carrying article is provided. Also provided herein is a “tackymaterial” defining a substrate which receives a tacky adhesive fortrapping micro-sized particles such as dust mites.

SUMMARY OF THE INVENTION

The benefits and advantages of the present invention are achieved by awoven or nonwoven material, which could also be characterized as acomposite fibrous material or pad, with adhesive properties.

This invention first offers a tacky material comprising:

(A) a woven or nonwoven substrate which contains

-   -   (i) matrix fibers    -   (ii) optionally, a binder, and

(B) a tacky adhesive.

At least some portion of the matrix fibers is treated with the adhesiveto trap micro-particles. In one aspect, the matrix fibers are treatedwith an acaracidal compound.

Within the scope of this invention is a process for the production of atacky material comprising:

(A) producing or providing a woven or nonwoven substrate which contains

-   -   (i) matrix fibers and,    -   (ii) optionally, a binder; and

(B) adhering a tacky adhesive to the substrate.

In specific embodiments of the invention, steps (A) and step (B) areperformed in a series of unitary steps in a continuous process. However,step (B) may be performed separately by different entities as part of aconverting process. In other words, a tacky adhesive is adhered to apreviously formed substrate in a converting process. In either event,the tacky adhesive may be adhered to the substrate by a manufacturer byspraying, rolling, printing or foaming. Alternatively, the tackyadhesive may be applied to the substrate by a consumer by spraying theadhesive from an aerosol can or a pump spray onto the substrate.

A process for immobilizing and containing pests including allergenproducing pests is also provided. The process comprises placing on oradhering to a surface of a mattress or other cushion of a bed, a pillow,a furniture cushion for an office, a dwelling or a vehicle the tackymaterial describe above.

Also provided herein is a filter element for filtering a fluidizedstream of materials. In one aspect, the filter element includes:

(A) a filter housing, and

(B) the tacky material of the present invention.

The filter element may be sized to fit a residential air conditioningunit. The filter housing may house a plurality of layers of the tackymaterial. The fluidized stream may be a gas or a liquid.

A method for containing allergens adjacent an allergen-bearing articleis also provided herein. In one aspect, the method comprises the stepsof: providing a tacky material, the tacky material comprising a woven ornonwoven substrate which contains matrix fibers and, optionally, abinder, and a tacky adhesive; placing the tacky material adjacent theallergen-bearing article; trapping allergens moving into or out of theallergen-bearing article within the tacky material; removing the tackymaterial from the allergen-bearing article; and disposing of theallergen-bearing article.

The allergens may be dust mites; the allergen-bearing article may be amattress; and the step of placing the tacky material adjacent theallergen-bearing article may involve spreading the tacky material overat least an upper surface of the mattress.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 presents a perspective view of a multistrata substrate tackymaterial 100. FIG. 1 depicts a top layer or strata 10; the tackymaterial 100, with an upper intermediate stratum 20, top surface 22, andbottom surface 24. FIG. 1 also shows a lower intermediate nonwovenmaterial layer 30, with a top surface 32 and bottom surface 34. Alsoshown is a release liner 40 and a light-weight container 50. Thelight-weight container 50 has a water-tight interior 52, a removablesealing member 58 and an upper lip 56.

FIG. 2 presents a photograph of a padformed sample taken at amagnification of 150×.

FIG. 3 shows a scanning electron micrograph of a padformed sample withdust retention taken at a magnification of 150×.

FIG. 4 is a micrograph of a cross-section of a Pilot Plant sample ofNTL3, Substrate 1 coated with the Flexcryl 1625 adhesive. The image ismagnified at 90×.

FIG. 5 is a micrograph image of nonwoven material NLT3 substrate after a25-day test.

FIG. 6 is a micrograph image of an NTL3 layer after a 25 day test periodwhere the magnification is set at 150×.

FIG. 7 provides a micrograph of the layers after 25 days of use at amagnification of 400×.

FIG. 8 provides a micrograph of the layers after 25 days of use at amagnification of 800×.

FIG. 9 provides a still image of an NTL3 substrate with American housedust mites. All but 2 dust mites (circled) were immobilized by an NTL3adhesive barrier.

FIG. 10 provides a still image from a video showing all dust mitesmoving freely on a mattress encasement product without adhesive.

FIG. 11 presents a micrograph showing a dried dust mite a dust mitelarva trapped by an NTL3 barrier material at 200× magnification.

FIG. 12 presents a micrograph showing a dust mite trapped by an NTL3substrate 1 barrier material at 180 magnification.

FIG. 13 presents a micrograph showing the filter media having captured200 mesh activated carbon applied to an NTL3 Substrate 1 barrier fabricat a magnification of 60×.

FIG. 14 presents a micrograph showing the filter media having captured200 mesh activated carbon applied to an NTL3 Substrate 1 barrier fabricat a magnification of 250×.

FIG. 15 shows an image of a representative frame used for ASHRAE 52.2testing at Blue Heaven Technologies.

FIG. 16 provides a scanning electron micrograph of NTL3 taken at amagnification of 2000× illustrating dust re-wetting capability ofFLEXCRYL® 1625.

FIG. 17 provides a scanning electron micrograph of NTL3 taken at amagnification of 1500× illustrating dust re-wetting capability ofFLEXCRYL® 1625.

FIGS. 18A-D provide graphical representations of data for initialairflow resistance (in WG) testing for substrates AFM1 (FIG. 18A), AFM2(FIG. 18B), AFM3 (FIG. 18C), and AFM2X2 (FIG. 18D). Data is provided asAirflow in CFM over resistance in WG.

FIGS. 19A-D provide graphical representations of data for particleremoval efficiency testing for substrates AFM1 (FIG. 19A), AFM2 (FIG.19B), AFM3 (FIG. 19C), and AFM2X2 (FIG. 19D). Data is provided asremoval efficiency in percentage over particle diameter in micromolar.

DETAILED DESCRIPTION

The present invention advantageously provides for a nonwoven substrate,which provides allergen-retaining layers capable of trapping variousallergens. The invention provides for a tacky material comprising thesubstrate with a tacky adhesive for use in a variety of filter typeapplications. In certain embodiments, the substrate may optionallycontain a pest control substance. These and other aspects of theinvention are discussed more in the detailed description and examples.

The terms used in this specification generally have their ordinarymeanings in the art, within the context of this invention and in thespecific context where each term is used. Certain terms are definedbelow to provide additional guidance in describing the compositions andmethods of the invention and how to make and use them.

DEFINITIONS

As used herein, the term “matrix fiber” refers to any natural orsynthetic fiber, or mixtures thereof. Natural fibers may includecellulose-based fibers such as those derived from wood pulp or cottonlinter pulp.

The term “substrate” may refer to a single layer of material or multiplelayers of material bonded together.

The term “tacky adhesive” refers to an adhesive that is eitherinherently tacky, or has been tackified by mixture with or applicationof a tackifier.

“Allergen-carrying articles” means any material in which dust-mites mayreside or populate. Non-limiting examples of such items include but arenot limited to mattresses, pillows, bolsters, duvets, quilts, articlesof clothing, including for example the insulating lining of jackets,sleeping bags, furniture, furniture cushions, cushions used in boats andrecreational vehicles and any other upholstered or padded item which mayharbor dust mites and related allergens.

The term “tack” refers to a sticky or adhesive quality or condition. A“tacky material” is any substance that is capable of holding materialstogether in a functional manner by surface attachment that resistsseparation.

The term “pressure sensitive adhesive” means an adhesive material whichbonds to adherend surfaces at room temperature immediately as lowpressure is applied, or which requires only pressure application toeffect permanent adhesion to an adherent.

The term “release layer” may be used interchangeably with the termsliner, release film, release liner and release sheet.

The term “weight percent” is meant to refer to the quantity by weight ofa compound in the material as a percentage of the weight of the materialor to the quantity by weight of a constituent in the material as apercentage of the weight of the final nonwoven product.

The term “basis weight” as used herein refers to the quantity by weightof a compound over a given area. Examples of the units of measureinclude grams per square meter as identified by the acronym (gsm).

As used in the specification and the appended claims, the singular forms“a,” “an” and “the” include plural referents unless the context clearlydictates otherwise. Thus, for example, reference to “a compound”includes mixtures of compounds.

The term “about” or “approximately” means within an acceptable errorrange for the particular value as determined by one of ordinary skill inthe art, which will depend in part on how the value is measured ordetermined, i.e., the limitations of the measurement system. Forexample, “about” can mean within 3 or more than 3 standard deviations,per the practice in the art. Alternatively, “about” can mean a range ofup to 20%, preferably up to 10%, more preferably up to 5%, and morepreferably still up to 1% of a given value. Alternatively, particularlywith respect to biological systems or processes, the term can meanwithin an order of magnitude, preferably within 5-fold, and morepreferably within 2-fold, of a value.

Allergen Trap Substrate

An allergen trap is disclosed herein. The allergen trap is generallyreferred to herein as a “tacky material.” The tacky material serves as afiltering medium for capturing allergens. Preferably, the tacky materialserves to capture dust mites by providing a tacky characteristic to alayer or a “matrix” of fibers. The tacky material may define a structurefor covering an allergen-bearing material such as a bed mattress, it maydefine a filtering medium in an air or other fluid filtering device, ormay serve other micro-particle-trapping functions.

The tacky material first includes a substrate. The substrate may befabricated or derived or made from woven or nonwoven fibers. In onespecific embodiment, the substrate is made from nonwoven fibers. A widevariety of natural and synthetic fibers are suitable for use as matrixfibers for the substrate. Preferred matrix fibers are cellulosic fibers,though synthetic fibers or a mixture of cellulosic and synthetic fibersmay be employed. In one aspect, the matrix fibers are any synthetic orcellulosic fiber that does not melt or dissolve to any degree during theformation or bonding of the nonwoven fibers.

Cellulosic fibrous materials suitable for use in the substrate of thepresent invention include both softwood fibers and hardwood fibers. SeeM. J. Kocurek & C. F. B. Stevens, Pulp and Paper Manufacture—Vol. 1:Properties of Fibrous Raw Materials and Their Preparation for Pulping,The Joint Textbook Committee of the Paper Industry, pp. 182 (1983),which is hereby incorporated by reference in its entirety. Exemplary,though not exclusive, types of softwood pulps are derived from slashpine, jack pine, radiata pine, loblolly pine, white spruce, lodgepolepine, redwood, and Douglas fir. North American southern softwoods andnorthern softwoods may be used, as well as softwoods from other regionsof the world. Hardwood fibers may be obtained from oaks, genus Quercus,maples, genus Acer, poplars, genus Populus, or other commonly pulpedspecies. In general, softwood fibers are preferred due to their longerfiber length as measured by T 233 cm-95, and southern softwood fibersare most preferred due to a higher coarseness as measured by T 234cm-84, which leads to greater intrinsic fiber strength as measured bybreaking load relative to either northern softwood or hardwood fibers.

One particularly suitable cellulose fiber is bleached Kraft southernpine fibers sold under the trademark FOLEY FLUFFS® (Buckeye TechnologiesInc., Memphis, Tenn.). Also preferred is cotton linter pulp, chemicallymodified cellulose such as cross-linked cellulose fibers and highlypurified cellulose fibers, such as Buckeye HPF, each available fromBuckeye Technologies Inc., Memphis, Tenn. Other suitable cellulosefibers include those derived from Esparto grass, bagasse, jute, ramie,kenaff, sisal, abaca, hemp, flax and other lignaceous and cellulosicfiber sources.

The fibrous material may be prepared from its natural state by anypulping process including chemical, mechanical, thermomechanical (TMP)and chemithermomechanical pulping (CTMP). These industrial processes aredescribed in detail in R. G. Macdonald & J. N. Franklin, Pulp and PaperManufacture in 3 volumes; 2^(nd) Edition, Volume 1: The Pulping of Wood,1969; Volume 2: Control, Secondary Fiber, Structural Board, Coating,1969, Volume 3: Papermaking and Paperboard Making, 1970, The jointTextbook Committee of the Paper Industry, and in M. J. Kocurek & C. F.B. Stevens, Pulp and Paper Manufacture, Vol. 1: Properties of FibrousRaw Materials and Their Preparation for Pulping, The Joint TextbookCommittee of the Paper Industry, p. 182 (1983), both of which are herebyincorporated by reference in their entirety. Preferably, the fibrousmaterial is prepared by a chemical pulping process, such as a Kraft orsulfite process. The Kraft process is especially preferred. Pulpprepared from a southern softwood by a Kraft process is often calledSSK. In a similar manner, southern hardwood, northern softwood andnorthern hardwood pulps are designated SHK, NSK & NHK, respectively.Bleached pulp, which is fibers that have been delignified to very lowlevels of lignin, are preferred, although unbleached Kraft fibers may bepreferred for some applications due to lower cost, especially ifalkaline stability is not an issue. Thermomechanical cellulose fiber maybe used. Desirably, the cellulose fiber for use as a matrix fiber hasbeen derived from a source which is one or more of Southern SoftwoodKraft, Northern Softwood Kraft, hardwood, eucalyptus, mechanical,recycle and rayon, but preferably Southern Softwood Kraft, NorthernSoftwood Kraft, or a mixture thereof, and more preferably, SouthernSoftwood Kraft.

The cellulose or fluff fibers may be blended with synthetic fibers suchas polyester, nylon, polyethylene or polypropylene. Alternatively, onlysynthetic fibers may be employed in the substrate. Synthetic fiberssuitable for use as a matrix fiber include cellulose acetate,polyolefins (including polyethylene and polypropylene), nylon, polyester(including polyethylene terephthalate (PET)), vinyl chloride, andregenerated cellulose such as viscose rayon, glass fibers, ceramicfibers, and the various bicomponent fibers known in the art. Whilebicomponent fibers may serve as matrix fibers in the nonwoven materialof this invention, they will be more fully described and discussed belowin the context of their role as a binder fiber.

Other synthetic fibers suitable for use in various embodiments as matrixfibers or as bicomponent binder fibers for the substrate include fibersmade from various polymers including, by way of example and not bylimitation, acrylic, polyamides (such as, for example, Nylon 6, Nylon6/6, Nylon 12, polyaspartic acid, polyglutamic acid, and so forth),polyamines, polyimides, polyacrylics (such as, for example,polyacrylamide, polyacrylonitrile, esters of methacrylic acid andacrylic acid, and so forth), polycarbonates (such as, for example,polybisphenol A carbonate, polypropylene carbonate, and so forth),polydienes (such as, for example, polybutadiene, polyisoprene,polynorbornene, and so forth), polyepoxides, polyesters (such as, forexample, polyethylene terephthalate, polybutylene terephthalate,polytrimethylene terephthalate, polycaprolactone, polyglycolide,polylactide, polyhydroxybutyrate, polyhydroxyvalerate, polyethyleneadipate, polybutylene adipate, polypropylene succinate, and so forth),polyethers (such as, for example, polyethylene glycol (polyethyleneoxide), polybutylene glycol, polypropylene oxide, polyoxymethylene(paraformaldehyde), polytetramethylene ether (polytetrahydrofuran),polyepichlorohydrin, and so forth), polyfluorocarbons, formaldehydepolymers (such as, for example, urea-formaldehyde,melamine-formaldehyde, phenol formaldehyde, and so forth), naturalpolymers (such as, for example, cellulosics, chitosans, lignins, waxes,and so forth), polyolefins (such as, for example, polyethylene,polypropylene, polybutylene, polybutene, polyoctene, and so forth),polyphenylenes (such as, for example, polyphenylene oxide, polyphenylenesulfide, polyphenylene ether sulfone, and so forth), silicon containingpolymers (such as, for example, polydimethyl siloxane, polycarbomethylsilane, and so forth), polyurethanes, polyvinyls (such as, for example,polyvinyl butyral, polyvinyl alcohol, esters and ethers of polyvinylalcohol, polyvinyl acetate, polystyrene, polymethylstyrene, polyvinylchloride, polyvinyl pryrrolidone, polymethyl vinyl ether, polyethylvinyl ether, polyvinyl methyl ketone, and so forth), polyacetals,polyarylates, and copolymers (such as, for example,polyethylene-co-vinyl acetate, polyethylene-co-acrylic acid,polybutylene terephthalate-co-polyethylene terephthalate,polylauryllactam-block-polytetrahydrofuran, and so forth).

The matrix fibers desirably are present in the substrate in an amount offrom about 30 percent by weight to about 95 percent by weight based onthe total weight of the material, more desirably, from about 55 percentto about 90 percent by weight based on the total weight of the material,preferably in an amount of about 75 percent by weight to about 95percent by weight.

As noted, the fiber matrix in the substrate may optionally include abinder. Binders suitable for use in the nonwoven material may be variousbicomponent binder fibers or mixtures thereof, various latices ormixtures thereof, or bicomponent fibers or mixtures thereof incombination with various latices or mixtures thereof, which may bethermoplastic, thermosetting or a mixture thereof. Thermoplastic powdersmay be used in various embodiments, and may be included in the nonwovenas a fine powder, chip or in granular form. In addition, binders havingdense fine powder filler such as, for example, calcium carbonate,various kinds of clay, such as, for example, bentonite and kaolin,silica, alumina, barium sulfate, talc, titanium dioxide, zeolites,cellulose-type powders, diatomaceous earth, barium carbonate, mica,carbon, calcium oxide, magnesium oxide, aluminum hydroxide, pulp powder,wood powder, polymer particles, chitin and chitin derivatives aresuitable for use in forming the substrate.

Various latex binders are suitable for use in the nonwoven material ofthis invention, such as, for example, ethyl vinyl acetate copolymerssuch as AirFlex 124® offered by Air Products of Allentown, Pa. AirFlex124® is used with 10 percent solids and 0.75 percent by weight AEROSOL®OT which is an anionic surfactant offered by Cytec Industries of WestPaterson, N.J. Other classes of emulsion polymer binders such asstyrene-butadiene and acrylic binders may also be used. BINDERS AIRFLEX®124 and 192 from Air Products, Allentown, Pa., optionally having anopacifier and whitener, such as, for example, titanium dioxide,dispersed in the emulsion may be used. Other classes of emulsion polymerbinders such as styrene-butadiene, acrylic, and carboxylated styrenebutadiene acrylonitrile (SBAN) may also be used. A carboxylated SBAN isavailable as product 68957-80 from Dow Reichhold Specialty Latex LLC ofResearch Triangle Park, NC. The Dow Chemical Company of Midland, Mich.is a source of a wide variety of suitable latex binders, such as, forexample, Modified Styrene Butadiene (SB) Latexes CP 615NA and CP 692NA,and Modified Styrene Acrylate (S/A) Latexes, such as, for example,CP6810NA. A wide variety of suitable latices are discussed in EmulsionPolymers, Mohamed S. El-Aasser (Editor), Carrington D. Smith (Editor),I. Meisel (Editor), S. Spiegel (Associate Editor), C. S. Kniep(Assistant Editor), ISBN: 3-527-30134-8, from the 217th AmericanChemical Society (ACS) Meeting in Anaheim, Calif. in March 1999, and inEmulsion Polymerization and Emulsion Polymers, Peter A. Lovell (Editor),Mohamed S. El-Aasser (Editor), ISBN: 0-471-96746-7, published byJossey-Bass, Wiley. Also useful are various acrylic, styrene-acrylic andvinyl acrylic latices from Specialty Polymers, Inc., 869 Old RichburgRd., Chester, S.C. 26706. Also useful are Rhoplex™ and Primal™ acrylateemulsion polymers from Rohm and Haas.

Bicomponent fibers having a core and sheath are known in the art. Manyvarieties are used in the manufacture of nonwoven materials,particularly those produced by airlaid techniques. Various bicomponentfibers suitable for use in the present invention are disclosed in U.S.Pat. Nos. 5,372,885 and 5,456,982, both of which are hereby incorporatedby reference in their entirety. Examples of bicomponent fibermanufacturers include KoSa (Salisbury, N.C.), Trevira (Bobingen,Germany) and ES Fiber Visions (Athens, Ga.).

Bicomponent fibers may incorporate a variety of polymers as their coreand sheath components. Bicomponent fibers that have a PE (polyethylene)or modified PE sheath typically have a PET (polyethyleneterephthalate)or PP (polypropylene) core. In one embodiment, the bicomponent fiber hasa core made of polyester and sheath made of polyethylene. The denier ofthe fiber preferably ranges from about 1.0 dpf to about 4.0 dpf, andmore preferably from about 1.5 dpf to about 2.5 dpf. The length of thefiber is preferably from about 3 mm to about 12 mm, more preferably fromabout 4.5 mm to about 7.5 mm.

Various geometric configurations can be used for the bicomponent fiberuseful in this invention, including concentric, eccentric,islands-in-the-sea, and side-by-side. The relative weight percentages ofthe core and sheath components of the total fiber may be varied.

In one aspect of the invention, the substrate has a basis weight of fromabout 35 gsm to about 1,000 gsm or, alternatively, has a basis weight offrom about 35 gsm to about 500 gsm or, alternatively still, has a basisweight of from about 35 gsm to about 250 gsm or, alternatively still,has a basis weight of from about 35 gsm to about 125 gsm, oralternatively still, has a basis weight of from about 35 gsm to about 75gsm. In another aspect, the substrate has a basis weight of from about100 gsm to about 1,000 gsm or, alternatively, has a basis weight of fromabout 250 gsm to about 1,000 gsm or, alternatively still, has a basisweight of from about 500 gsm to about 1,000 gsm. In yet another aspect,the substrate has a basis weigh of from about 100 gsm to about 1,000gsm, or alternatively from about 1500 gsm to about 500 gsm, oralternatively from about 150 gsm to about 300 gsm, or alternativelystill, from about 200 gsm to about 300 gsm, or from about 200 gsm toabout 220 gsm.

In another aspect, the substrate has a basis weight of from about 35 gsmto about 500 gsm and contains from about 30 weight percent to about 95weight percent matrix fibers and from about 5 weight percent to about 70weight percent of a binder where the weight percentages are based on thetotal weight of the nonwoven substrate. Optionally, the substrate maycontain from about 50 weight percent to about 95 weight percent matrixfibers and from about 5 weight percent to about 50 weight percent of abinder. Alternatively, the substrate may contain from about 75 weightpercent to about 95 weight percent matrix fibers and from about 5 weightpercent to about 25 weight percent of a binder.

In one embodiment of the invention, the substrate has a density of fromabout 0.035 g/cm³ to about 0.10 g/cm³.

In addition to being useful as a binder in the nonwoven materialdefining the substrate, a latice may be used on an outer surface of thematerial to control dusting. In this application, the amount used wouldbe in the range of about 1 to about 10 gsm on an individual surface.

The materials of the present invention may also include additivesincluding but not limited to ultra white additives, colorants, opacityenhancers, delustrants and brighteners, and other additives to increaseoptical aesthetics as disclosed in U.S. patent application Ser. No.10/707,598 filed Dec. 23, 2003, which is hereby incorporated byreference in its entirety.

In a preferred process suitable for commercial production, the nonwovenmaterial that serves as the matrix for the substrate is prepared as acontinuous airlaid web. The airlaid web is typically prepared bydisintegrating or defiberizing a cellulose pulp sheet or sheets,typically by hammermill, to provide individualized fibers. Rather than apulp sheet of virgin fiber, the hammermills or other disintegrators canbe fed with recycled airlaid edge trimmings and off-specificationtransitional material produced during grade changes and other airlaidproduction waste. Being able to thereby recycle production waste wouldcontribute to improved economics for the overall process. Theindividualized fibers from whichever source, virgin or recycle, are thenair conveyed to forming heads on the airlaid web-forming machine. Anumber of manufacturers make airlaid web forming machines suitable foruse in this invention, including Dan-Web Forming of Aarhus, Denmark, M&JFibretech A/S of Horsens, Denmark, Rando Machine Corporation, Macedon,N.Y. which is described in U.S. Pat. No. 3,972,092, Margasa TextileMachinery of Cerdanyola del Valles, Spain, and DOA International ofWels, Austria. While these many forming machines differ in how the fiberis opened and air-conveyed to the forming wire, they all are capable ofproducing the webs of this invention.

The Dan-Web forming heads include rotating or agitated perforated drums,which serve to maintain fiber separation until the fibers are pulled byvacuum onto a foraminous forming conveyor or forming wire. In the M&Jmachine, the forming head is basically a rotary agitator above a screen.The rotary agitator may comprise a series or cluster of rotatingpropellers or fan blades. Other fibers, such as a syntheticthermoplastic fiber, are opened, weighed, and mixed in a fiber dosingsystem such as a textile feeder supplied by Laroche S. A. of Cours-LaVille, France. From the textile feeder, the fibers are air conveyed tothe forming heads of the airlaid machine where they are further mixedwith the comminuted cellulose pulp fibers from the hammer mills anddeposited on the continuously moving forming wire. Where defined layersare desired, separate forming heads may be used for each type of fiber.

The airlaid web is transferred from the forming wire to a calender orother densification stage to densify the web, if necessary, to increaseits strength and control web thickness. The fibers of the web are thenbonded by passage through an oven set to a temperature high enough tofuse the included thermoplastic or other binder materials. Secondarybinding from the drying or curing of a latex spray or foam applicationmay occur in the same oven. The oven may preferably be a conventionalthrough-air oven or be operated as a convection oven, but may achievethe necessary heating by infrared or even microwave irradiation. Theairlaid web may be treated with flame retardants before or after heatcuring.

In a preferred embodiment of the inventions, the nonwoven structuremaking up the substrate is an airlaid structure, and the nonwovenmaterial is an airfelt or other nonbonded matrix of fiber or, whenbonded, an airlaid matrix.

The caliper, also know as the thickness, for the substrate may rangefrom about 1 mm to about 60 mm, while in some desirable embodiments itmay be from about 1 mm to about 30 mm, or from about 1 mm to about 15mm, or from about 1 mm to about 7 mm, or from about 1 mm to about 3 mm.

The nonwoven structure has an airflow resistance of from about 500 toabout 10,000 Rayls (NS/m³), or desirably in some embodiments, of fromabout 500 to about 5,000 Rayls (NS/m³), or desirably in someembodiments, of from about 500 to about 3,000 Rayls (NS/m³). By means ofthe selection of materials used to make the nonwoven structure, it ispossible to produce materials with a variety of airflow resistances.Airflow resistance will also depend upon the application and number oflayers employed. Air filtration applications may require a lower airflowresistance.

Various materials, structures and manufacturing processes useful in thepractice of this invention are disclosed in U.S. Pat. Nos. 6,241,713;6,353,148; 6,353,148; 6,171,441; 6,159,335; 5,695,486; 6,344,109;5,068,079; 5,269,049; 5,693,162; 5,922,163; 6,007,653; 6,355,079;6,403,857; 6,479,415; 6,562,742; 6,562,743; 6,559,081; 6,495,734;6,420,626; in U.S. patent applications with serial numbers and filingdates, Ser. No. 09/719,338 filed Jan. 17, 2001; Ser. No. 09/774,248filed Jan. 30, 2001; and Ser. No. 09/854,179 filed May 11, 2001, and inU.S. Patent Application Publications or PCT Application Publications US2002/0074097 A1, US 2002/0066517 A1, US 2002/0090511 A1, US 2003/0208175A1, US 2004/0116882 A1, US 2004/0020114 A1, US 2004/0121135 A1, US2005/0004541 A1, and WO 2005/013873 A1, and PCT/U504/43030 claiming thebenefit of U.S. provisional patent application Ser. No. 60/569,980,filed May 10, 2004 and U.S. provisional patent application Ser. No.60/531,706, filed Dec. 19, 2003, and U.S. provisional patent applicationSer. No. 60/667,873, filed Apr. 1, 2005, all of which are herebyincorporated by reference in their entirety.

Tacky Adhesive

As noted, the substrate of the allergen trap is coated with or willotherwise receive a tacky material. Preferably, the tacky material is atackified pressure sensitive adhesive. The term “pressure sensitiveadhesive” generally refers to an adhesive which in dry form isaggressively and permanently tacky at room temperature and firmlyadheres to a variety of dissimilar surfaces upon contact without a needof more than finger or hand pressure. See Glossary of Terms Used inPressure Sensitive Tape Industry, Pressure Sensitive Tape Council(PSTC), Glenview, Ill., 1959, as quoted on page 345 in Encyclopedia ofPolymer Science and Engineering, Vol. 13, 1988, John Wiley & Sons, Inc.See also Pressure-Sensitive Formulation, by Istvan Benedek, ISBN 9 06764330 0, Publisher VSP, 2000.

Pressure sensitive adhesives typically include materials (e. g.,elastomers) that are either inherently tacky or that are tackified withthe addition of tackifying resins. They can be defined by the Dahlquistcriteria described in Handbook of Pressure Sensitive AdhesiveTechnology, D. Satas, 2nd ed., page 172 (1989) at use temperatures. Usetemperature will typically be room temperature, i.e., about 20° C. toabout 30° C. This criterion defines a good pressure-sensitive adhesiveas one having a one-second creep compliance of greater than 1×10⁻⁶cm²/dyne. Alternatively, since modulus is, to a first approximation, theinverse of compliance, pressure sensitive adhesives may be defined asadhesives having a modulus of less than 1×10⁶ dynes/cm².

Another suitable definition of a pressure sensitive adhesive is that itpreferably has a room temperature storage modulus within the areadefined by the following points as plotted on a graph of modulus versusfrequency at 25° C.: a range of moduli from approximately 2×10⁵ to 4×10⁵dynes/cm² at a frequency of approximately 0.1 radian/second (0.017 Hz),and a range of moduli from approximately 2×10⁶ to 8×10⁶ dynes/cm² at afrequency of approximately 100 radians/second (17 Hz) (for example, seeFIG. 8-16 on p. 173 of Handbook of Pressure Sensitive AdhesiveTechnolga, D. Satas, 2nd ed., (1989)).

Other methods of identifying a pressure sensitive adhesive are alsoknown. Any of these methods of identifying a pressure sensitive adhesivemay be used to define pressure sensitive adhesives of the presentinvention. Major classes of pressure sensitive adhesives includeacrylics, polyurethanes, poly-alpha-olefins, silicones, and tackifiednatural and synthetic rubbers. Some examples of synthetic rubbersinclude tackified linear, radial (e.g., star), tapered, and branchedstyrenic block copolymers, such as styrene-butadiene-styrene,styrene-ethylene/butylene-styrene, and styrene-isoprene-styrene.

The pressure-sensitive adhesive material can include a single,pressure-sensitive adhesive, a mixture of several pressure-sensitiveadhesives, or a mixture of a pressure-sensitive adhesive and a materialthat is a non-pressure-sensitive adhesive. An example of anon-pressure-sensitive adhesive is a nontacky thermoplastic material.Examples of some pressure-sensitive adhesive blends are described in PCTInternational Applications having numbers WO 97/23577, WO 97/23249, andWO 96/25469, such descriptions being incorporated herein by reference intheir entirety.

A variety of pressure-sensitive adhesives are available for applicationto the fibrous material employed herein. The pressure sensitive adhesiveis present in an amount from about 5 gsm to about 300 gsm. Thepressure-sensitive adhesive may be a rubber substance such as naturalrubber latex, butadiene rubber latex or styrene-butadiene rubber latex.The pressure-sensitive adhesive may alternatively be an acrylate ormethacrylate copolymer, a self-tacky poly-α-olefin, a polyurethane, or aself-tacky or tackified silicone.

It is desirable to use a water-based pressure-sensitive adhesive. Thisavoids the difficulties encountered with solvent-based adhesives,including flammability and environmental issues. It is perceived that awater-based adhesive will also avoid issues of human toxicity, as oneapplication for the tacky material of the present invention is in use asa mattress cover. In other words, the adhesive is applied to a fibrousmaterial that will, in certain contexts and applications, be in closeproximity to a consumer's respiratory system. Another application willbe as a layer or medium in an air filtration system which is designed toimprove air quality, meaning that non-toxic materials are preferred.

At least a portion of the fiber matrix is impregnated with thepressure-sensitive adhesive. Preferably, the adhesive is a rubbersubstance that is either a natural rubber latex or a synthetic rubberlatex. Examples of a synthetic rubber latex include butadiene rubberlatex and styrene-butadiene rubber latex. It is preferred that thesynthetic rubber material be inherently tacky, or self-tacky. Morespecific examples of inherently tacky synthetic rubberpressure-sensitive adhesives include butyl rubber, a copolymer ofisobutylene with less than 3 percent isoprene, polyisobutylene, ahomopolymer of isoprene, polybutadiene, or styrenel-butadiene rubber.

The rubber material is preferably provided in the form of an aqueouslatex emulsion which can be sprayed onto the fibrous material. Sprayingprovides the best opportunity for the emulsion to penetrate fibersmaterial beneath the immediate surface being sprayed. The latex emulsionis preferably applied to the substrate while the substrate is in asubstantially dry condition. However, the emulsion may alternatively beapplied to the substrate in a pre-wetted condition. This permits thelatex emulsion to further impregnate the hydroentangled material.

In some applications it is desirable that the adhesive material beapplied only on the outer surface of the substrate. In this case, it ispreferred that the latex emulsion be printed, foamed, or rolled onto thefibrous material. Alternatively, a light spray may be applied, followedimmediately by drying in an oven.

In order to improve the particle-entrapping characteristic of thesubstrate, it is desirable that the adhesive be “tackified.” A“tackifier” is a substance that will increase the coefficient offriction of the material being treated, thereby increasing the abilityof the pressure-sensitive adhesive to attract and retain dust andallergen particles. Generally, when additives (such as a tackifier) areused to alter properties of pressure sensitive adhesives, the additivesshould be miscible with the pressure sensitive adhesive or formhomogeneous blends at the molecular level.

General examples of suitable tackifiers include, but are not limited to,acetate, acrylic polymer, polystyrene and butadiene-styrene. Some typesof pressure sensitive adhesives have been modified with tackifiedthermoplastic elastomers (e.g., styrene-isoprene-styrene blockcopolymers), thermoplastics (e.g., polystyrene, polyethylene, orpolypropylene), and elastomers (e.g., polyolefins, natural rubbers, andsynthetic rubbers). For example, thermoplastic materials have been addedto acrylic pressure sensitive adhesives to add tack. Such materials aredescribed in International Publication Nos. WO 97/23577 and WO 96/25469(each to Minnesota Mining and Manufacturing Co.).

As used herein, a thermoplastic elastomer (i.e., thermoplastic rubber)is a polymer having at least two homopolymeric blocks or segments,wherein at least one block has a Tg of greater than room temperature(i.e., about 20° C. to about 25° C.) and at least one block has a Tg ofless than room temperature. As used herein, “Tg” is a measurement knownin the art as the glass transition temperature at which an amorphousepolymer or regions thereof change from hard condition to a viscous orrubber-like conditions. In a thermoplastic elastomer these two blocksare generally phase separated into one thermoplastic glassy phase andone rubbery elastomeric phase. A radial block copolymer is a polymerhaving more than two arms that radiate from a central core (which canresult from the use of a multifunctional coupling agent, for example),wherein each arm has two or more different homopolymeric blocks orsegments as discussed above. See, for example, the Handbook of PressureSensitive Adhesive Technology, D. Satas, 2nd ed., Chapter 13 (1989).

Natural rubber pressure-sensitive adhesives generally contain masticatednatural rubber, tackified with one or more tackifying resins. They mayalso contain one or more antioxidants.

Synthetic rubber pressure sensitive adhesives are also contemplated bythe present invention. Styrene block copolymer pressure-sensitiveadhesives generally comprise elastomers of the A-B or A-B-A type,wherein, in this context, A represents a thermoplastic polystyrene blockand B represents a rubbery block of polyisoprene, polybutadiene, orpoly(ethylene/butylene), and tackifying resins. Examples of the variousblock copolymers useful in block copolymer pressure-sensitive adhesivesinclude linear, radial, star, and tapered block copolymers. Specificexamples include copolymers such as those available under the tradedesignations KRATON™ from Shell Chemical Company of Houston, Tex., andEUROPRENE SOL™ from EniChem Elastomers Americas, Inc., also of Houston,Tex. Examples of tackifying resins for use with such styrene blockcopolymers include aliphatic olefin-derived resins, rosin esters,hydrogenated hydrocarbons, polyterpenes, terpene phenolic resins derivedfrom petroleum or terpentine sources, polyaromatics, cournarone-indeneresins, and other resins derived from coal tar or petroleum and havingsoftening points above about 85° C.

Pressure sensitive adhesives may also be acrylic pressure sensitiveadhesives. Acrylic pressure-sensitive adhesives comprise about 80 wt %to about 100 wt % isooctyl acrylate and up to about 20 wt % acrylicacid. The acrylic pressure-sensitive adhesives may be inherently tackyor tackified using a tackifier such as a rosin ester, an aliphaticresin, or a terpene resin. (Meth)acrylate (i.e., acrylate andmethacrylate or “acrylic”) pressure-sensitive adhesives generally have aglass transition temperature of about −20° C. or less and typicallyinclude an alkyl ester component such as, for example, isooctylacrylate, 2-ethyl-hexyl acrylate, and n-butyl acrylate, and a polarcomponent such as, for example, acrylic acid, methacrylic acid, ethylenevinyl acetate, and N-vinyl pyrrolidone.

An example of an acrylic pressure-sensitive adhesive that may be used ona nonwoven substrate is 3M Fastbone™ Insulation Adhesive 49. 3MFastbone™ is an aqueous dispersion of an acrylate polymer. Anotherexample is an ethylene-vinyl acetate copolymer available as DUR-O-SET®manufactured by Vinamul®. DUR-O-SET® is sold as a spray-on adhesiveemulsion. Yet another example is FLEXCRYL® 1625, which is a high-solids,water-based vinyl acrylate pressure sensitive adhesive. It is sold as anacrylic emulsion and manufactured by Air Products and Chemicals, Inc.,Allentown, Pa. Still another example is NACOR® 38-088A, which is anaqueous emulsion of an acrylic copolymer available from National Starchand Chemical Co. of Bridgewater, N.J.

The pressure sensitive adhesives of the present invention may includepoly-α-olefin pressure-sensitive adhesives. Poly-α-olefinpressure-sensitive adhesives, also called poly(1-alkene)pressure-sensitive adhesives, generally comprise either a substantiallyuncrosslinked polymer or an uncrosslinked polymer that may haveradiation activatable functional groups grafted thereon as described inU.S. Pat. No. 5,209,971 (Babu et al.) (the disclosure of which isincorporated herein by reference in its entirety). Useful poly-α-olefinpolymers include, for example, C₃-C₁₈ poly(1-alkene) polymers. Thepoly-α-olefin polymer may be inherently tacky and/or include one or moretackifying materials such as resins derived by polymerization of C₅-C₉unsaturated hydrocarbon monomers, polyterpenes, synthetic polyterpenes,and the like.

Silicone pressure-sensitive adhesives may also be used on the presentinvention. Silicone pressure-sensitive adhesives comprise two majorcomponents, a polymer or gum and a tackifying resin. The polymer istypically a high molecular weight polydimethylsiloxane orpolydimethyldiphenylsiloxane, that contains residual silanolfunctionality (SiOH) on the ends of the polymer chain, or a blockcopolymer comprising polydiorganosiloxane soft segments and ureaterminated hard segments. The tackifying resin is generally athree-dimensional silicate structure that is endcapped withtrimethylsiloxy groups (OSiMe₃) and also contains some residual silanolfunctionality. Silicone pressure-sensitive adhesives are described inU.S. Pat. No. 2,736,721, which is incorporated herein by reference.Silicone urea block copolymer pressure-sensitive adhesives are describedin U.S. Pat. No. 5,461,134, and PCT International Application Nos. WO96/34028 and WO 96/35458, also incorporated herein by reference.

The tackifier is preferably applied in an aqueous vehicle, that is, anemulsion, along with the adhesive. Thereafter, the fibrous material isdried, preferably in an oven, to cause the carrier to retain the rubberor other adhesive material.

While a wide variety of adhesives are suitable for use in this inventionon a wide variety of substrates, it is desirable that the material withtack exhibit adequate performance in a Dust Capture Performance Test.Example 4 below provides a detailed description of the execution of thistest. In this test, it is desirable that a material with tack having abasis weight of from about 35 gsm to about 125 gsm when tested with a0.5 g sample of Arizona Test Dust (“ATD”) have a Dust Capture of about60% or greater, more desirably, the Dust Capture is about 70% orgreater, still more desirably, the Dust Capture is about 80% or greater,preferably, the Dust Capture is about 90% or greater. In one instance,dust mite allergens and feline allergens are reduced by about 95% ormore in an Allergen Barrier Test.

In a specific embodiment, the tacky adhesive is applied to the substrateat the time of manufacture. The product is then shipped to the customeror user as a final product. However, in one aspect the user will openthe packaging and then apply the tacky adhesive after the substrate hasbeen placed adjacent to an allergen-bearing article. Application of theadhesive may be by a pump spray or an aerosol can. The applicator may beincluded in the packaging with the substrate, or may be sold separatelyby the manufacturer or other source as an “after-market” product.

Pest Control Substances

In addition to a tacky adhesive, the substrate may also be treated witha miticidal compound or substance. The miticide (or acaricide or otherpesticide) is preferably applied to the substrate after the fiber matrixhas received a tacky adhesive. Alternatively, the miticide may bedissolved or suspended within the binder for the nonwoven material. Themiticidal compound or substance will be a material that is nontoxic tohumans and pets. Acceptable miticides include pyrethroid compounds suchas viz permethrin, cypermethrin and deltamethrin, both of which areavailable. Such pyrethroids may be mixed in a 10% by weight emulsifiableconcentrate formulation and sprayed onto the substrate. Particularexamples of permethrin that may be used are Permanone™ WP 25 availablefrom AgrEvo of Montvale, N.J. and Smite™ from Medachieve, Inc. inWashington Courthouse, Ohio. Pyrethrin also comes in a natural or“botanical” form. Pyrethrin is an extract of the crushed dried flowersof Chrysanthemum cinerarifolium, a perennial daisy like plant fromKenya.

Alternatively, borate-type compounds such as those disclosed in U.S.Pat. Nos. 5,587,221 and 5,672,362 may be used, the disclosures of whichare incorporated herein by reference in their entireties. Oneborate-based product that may be used in the invention herein issupplied as Dustmitex™, which is available from The Ecology Works of SanRafael, Calif. Dustmitex™ is a formulated borate compound sold in powderform. Rotenone, also known as Cube root, is known to be an effectivebotanical in controlling a number of insects, including mites. Rotenonecomes from the Derris family of plants grown in the tropics throughoutthe world. Rotenone acts as an insect stomach poison.

As an alternative to an acaricidal substance, an allergen neutralizermay be applied to the substrate of the tacky material. One option of aneutralizer is a tannic acid material. Such a material is foundnaturally in strong teas such as black tea. Tannic acid is considered a“denaturant.” Tannic acid is capable of breaking down mite fecalallergens. Allergen denaturation is accomplished by the phenol groups oftannic acid, which polymerize the allergens, making them morehydrophobic and less allergenic. However, a disadvantage to the use oftannic acid is that it stains fabric.

Tannic acid powders are available on the market, such as ALLERSEARCH XMITE™ powder (available from Alkaline Corporation of Oakhurst, N.J.)which provides a benzyl tannate complex in a cellulose aqueous slurry.The product may be sprinkled on carpets or other areas where miteallergens are found. This product is available on-line throughwww.healthgoods.com or www.allersearch-us.com. In the present invention,such a dust mite allergen neutralizer may be sprinkled lightly onto thesubstrate where it is then held by the tacky adhesive.

As another alternative to a pesticide, an insect growth regulator (IGR)may be applied to the matrix fibers. This may be done either byattaching the insect growth regulator to the sticky adhesive, or bydissolving or suspending the growth regulator within the binder. Growthinhibitors or insect growth regulators (any of which is commonly knownas an IGR) are products or materials that interrupt or inhibit the lifecycle of a pest. IGR's operate under the principle that if the pestcannot reach adulthood, it is not capable of reproducing. By inhibitingthe maturity of an insect, the IGR keeps the insect from reaching thecritical adult stage, thus stopping the life cycle and infestation.

Various IGR compounds have been developed. Methoprene and hydroprene areboth considered to have beneficial effect on dust mite populations.Methoprene and hydroprene are synthetic compounds that mimics theinsect's juvenile hormone. They are also considered to have low humantoxicity.

Use of Multiple Layers

The nonwoven substrate may define more than one layer of material. Inthis respect, the tacky material may optionally include a second, athird, or even a fourth layer of nonwoven material.

In one embodiment, a thin second layer of nonwoven material is appliedalong one surface of a first nonwoven stratum. This thin second layer isreferred to herein as a “scrim.” The optional scrim preferably has abasis weight of from about 8 gsm to about 200 gsm. As a result of themanufacturing process, the scrim is integral with a surface of thenonwoven material that makes up the first layer. In one aspect, thescrim is used as a carrier sheet in an airlaid process, with theinterior surface of the scrim in direct contact with the interiorsurface of the nonwoven first layer. In a preferred method of productionusing airlaying techniques, the nonwoven first layer is formed directlyon the interior surface of the scrim. However, the process may combinethe scrim with a pre-formed airlaid or other nonwoven material in aconverting process.

The nonwoven scrim, or carrier, can be made from natural fibers such ascellulose fibers. Synthetic fibers of various sorts which arespun-bonded, meltblown or spunlaced may also be used. A wide variety ofmaterials including, cloth, textile, unbacked carpeting and other wovenmaterials made of various natural fibers, synthetic fibers and mixturesthereof may further be used as carriers. Examples are 3024 cellulosiccarrier tissue, 18 gsm, from Cellu Tissue Co., now Cellu Tissue Neenah,249 N. Lake Street, Neenah, Wis. 54956, needle-punched nonwoven fabrics,spunbonded polypropylene nonwovens, such as Hybond™, a spunlaidthermalbonded soft fabric available in basis weights from 14 gsm to 20gsm and ULTRATEX™, a spunlaid (continuous filament) thermalbondedpolypropylene nonwoven in basis weights of 20, 40, 50, 60, 70, 100, 120,-and 150 gsm, from Texbond S.P.A., Via Fornaci 15/17, 38068 Rovereto(TN), Italy. Polyester spunbond nonwovens, with a uniform surface, hightear strength and high porosity, can be used. Polyester spunbond, whichis a manufactured sheet of randomly orientated polyester filamentsbonded by calendaring, needling, chemically or a combination of thesemethods in basis weights from 15 to 500 g/m² is available from JohnsManville Sales GmbH, Max-Fischer-Strasse 11, 86399 Bobingen/Germany. Ingeneral the scrim may be formed via the spunbond process, the melt-blownprocess, the spunlaced process, the carding process or a combination ofany of these processes, such as, for example,spunbond-melt-blown-spunbond or spunbond-meltblown-meltblown-spunbond.Of interest also are other useful materials such as those where thescrim is made of a polyester, such as, for example, polyethyleneterephthalate, polytrimethylene terephthalate and so forth, apolyolefin, such as, for example, polyethylene, polypropylene and soforth, polylactic acid, nylon or a combination of these materials.

While the scrim can have a basis weight of from about 8 gsm to about 200gsm, it may be desirable for the scrim to have a basis weight of fromabout 8 gsm to about 100 gsm, more desirable, from about 8 gsm to about75 gsm, or it may be preferable that the scrim has a basis weight offrom about 8 gsm to about 50 gsm, or even from about 8 gsm to about 25gsm.

In another embodiment of the tacky material of the present invention, alayer or stratum of nonwoven material impregnated with a tacky adhesiveis provided to form a tacky layer. The tacky layer is then placedbetween nonwoven material layers that do not have a tacky adhesiveapplied thereon. In this way, an allergen-carrying article (such as amattress) which receives the tacky material is not in immediate contactwith the tacky adhesive. Likewise, a user which sits or rests on thetacky material is not in immediate contact with the tacky adhesive. Theresult is that a tackier adhesive may be employed for the intermediatelayer. Further, tacky material units may be packaged one on top of theother without use of a release liner.

The adhesive of the tacky layer may be coextensively contiguous with amajor interior or exterior surface of the substrate. Alternatively, theadhesive may be coextensively contiguous with only one or more selectedareas of the substrate. The adhesive may be applied to a layer of matrixfibers after the layer is formed such that the steps are performed in aseries of unitary steps in a continuous process. Alternatively, thetacky adhesive may be adhered to a previously formed substrate in aconverting process.

In still another embodiment of the tacky material, a miticidal compoundis applied to a tacky layer between two non-tacky layers of nonwovenmaterial. The tacky layer having the miticidal compound may be placedadjacent a second tacky layer which does not have a miticidal compound.The two tacky layers are then sandwiched between two nonwoven layersthat do not have a tacky adhesive. In this way, a user which sits orrests on the tacky material is not in immediate contact with the tackyadhesive.

In yet another embodiment of the tacky material, an activated charcoalmaterial is applied to a tacky layer between two non-tacky layers ofnonwoven material. The tacky layer having the activated charcoalmaterial may be placed adjacent a second tacky layer which has amiticidal compound.

In another embodiment of the tacky material of the present invention, anouter nonwoven layer or strata of the substrate is sprayed with a tackyadhesive on an exterior surface. A release layer is then applied oradhered to the tacky adhesive. The release layer is non-tacky, andpermits multiple tacky material units to be stacked one on top of theother prior to or within packaging. The release liner is preferably leftin place after the tacky material is packaged and shipped to theultimate user. The release liner is peeled from the substrate prior toor shortly after placement of the tacky material onto anallergen-carrying article.

The material used for the liner is preferably matched to the type ofadhesive used on the substrate. Release liners include, for example,paper, metal foils, and polymeric films, that is, polyolefin,polyethylene, polyester, and plasticized vinyl films. Polyethylene andpolypropylene films are advantageous because they do not require aseparate coating (e.g. silicones) to provide a release surface.Silicone-coated polyester release liners are also known in the art.Release liners may also include woven or nonwoven fabrics which havebeen treated on at least one major surface, and preferably on both majorsurfaces, with a release agent such as silicone, perfluoropolyether,TEFLON™, and the like.

Method for Containing Allergens

A method for containing allergens is also disclosed herein. In oneembodiment, the method includes a step of providing a tacky material,such as tacky material 100 in FIG. 1. It is understood, however, thatthe tacky material may be any embodiment understood from the disclosuresabove. In this respect, the tacky material will include a substrate thatcontains matrix fibers that may be either woven or nonwoven, and whichmay be either natural, synthetic, or a combination. Further, the tackymaterial will include a tacky adhesive that is either impregnated withinone or more stratum of the substrate, or which is applied to a surfaceof the substrate or one of its stratum. At least a portion of the matrixfibers may be treated with a nontoxic miticidal compound.

The tacky material is placed over and, optionally, around anallergen-bearing article. Examples of such an article include amattress, a pillow or a furniture cushion. Over a period of time,allergens such as dust mites are trapped by the adhesive within thetacky material. After an additional period of time, the tacky materialis removed from the allergen-bearing article and disposed of A new tackymaterial is then provided.

Use of Tacky Material for Filtering

The tacky material may also be used as a filtering media. In thisrespect, the tacky material may be sized to be placed within a filterhousing. The tacky material may be the only medium used in the filterhousing, or may be used in combination with a charcoal filter, a HEPAfilter or other filtering media. Consistent with this arrangement, aprocess for immobilizing and containing allergens is provided.

In one embodiment of the invention, the substrate is used as itproduced, but cut to an appropriate size and attached over an airfilter. This simple use provides an inexpensive means for a high qualityfilter cartridge.

In addition, a filter element for filtering a fluidized stream ofmaterials is provided. The filter element includes a filter housing, andany embodiment of the tacky material disclosed above. In one aspect, thefilter element is the housing for an air mover in a house, or isotherwise sized to fit a residential air conditioning unit within theair stream. The filter housing may house a substrate defining aplurality of layers, including more than one layer having a tackyadhesive.

A process for filtration of a fluidized stream of materials is alsoprovided. The process includes the step of providing a tacky material inany embodiment disclosed above. The tacky material is incorporated intoa filtering element as a filtering medium. The fluidized stream ofmaterials is then passed through the tacky material in order to filtersuspended particulate matter or dissolved matter. The fluidized streammay, in one aspect, be air or another gas. The suspended particulatematter may contain dust, allergens, or a mixture thereof. In anotheraspect, the fluidizing stream is a liquid.

EXAMPLES

The following examples are merely illustrative of the present inventionand they should not be considered as limiting the scope of the inventionin any way.

Example 1 Basic Airlaid Structures

Nonwoven substrates were produced having dimensions of 0.3556 meters by0.3556 meters (14 inches by 14 inches). The substrates were producedusing a laboratory padformer that deposits individualized fibers on aforming wire under vacuum. Airfelts having basis weights of 40 gsm(grams per square meter), 45 gsm, 50 gsm, 80 gsm, and 100 gsm,respectively, were prepared on the padformer. The raw materials usedwere southern softwood Kraft fluff pulp, available as FOLEY FLUFFS® fromBuckeye Technologies Inc., Memphis, Tenn., and bicomponent binder fiberwith a polyethylene sheath over a polyester core, available as TypeT-255 with merge number 1661, which had a 2.2 dtex denier and 6-mmlength, made by Trevira GmbH of Bobingen, Germany.

Table 1 shows the amount of pulp and bicomponent fiber used in theexperimental substrates.

TABLE 1 Composition of Laboratory Padformed Samples Sample A Sample BSample C Sample D Sample E Raw Basis Wt. Basis Wt. Basis Wt. Basis Wt.Basis Wt. Material (gsm) (gsm) (gsm) (gsm) (gsm) Pulp - 35.0 40.0 45.060.0 80.0 FOLEY FLUFFS ® Southern Softwood Kraft Bicomponent 5.0 5.0 5.020.0 20.0 (T-255, Merge No. 1661) Total 40.0 45.0 50.0 80.0 100.0 (gsm)

Example 2 Airlaid Substrate

An airlaid substrate called NLT3 was prepared on a Dan-Web pilot scaleairlaid manufacturing unit at Buckeye Technologies, Inc. in Memphis,Tenn. The raw materials were (1) a southern softwood Kraft fluff pulp,available as FOLEY FLUFFS® from Buckeye Technologies Inc.; (2)bicomponent binder fiber with a polyethylene sheath over a polyestercore, available as Type T-255 with merge number 1663, made by TreviraGmbH of Bobingen, Fibervisions™; (3) AL-Adhesion polyolefin bicomponentfibers produced by Fibervisions; and (4) an ethylene vinyl acetate latexbinder available as AIRFLEX® 192 manufactured by Air Products. (AIRFLEX®192 usually has an opacifier and whitener, such as titanium dioxide,dispersed in the emulsion). Trevira's T-255 Merge No. 1663 bicomponentfiber has a denier of 2.2-dtex, and is 3-mm in length and a 50/50 ratioof polyester to polyethylene. Fibervision's™ AL-Adhesion bicomponentfibers consist of a polypropylene core and a polyethylene sheath.Fibervision™ AL-fibers are suitable for blends with wood pulp as theyhave an improved ability to bind cellulosic fibers and reduce dust tothe minimum.

The airlaid structure substrate NTL3 had a basis weight of 69.9 gsm andwas prepared according to the composition given in Table 2 on the pilotline.

TABLE 2 Composition of Pilot Example 1 (NLT3 Control) Basis WeightComponent of Substrate (gsm) Southern Softwood Pulp - FOLEY FLUFFS ®32.3 Bicomponent Fiber (PET/PE) - Trevira 1663 7.30 Fibervisions ™AL-Adhesion Fiber 29.1 EVA Latex Binder Spray - AIRFLEX ® 192 1.20 TotalBasis Weight 69.9

The first forming head added 29.1 gsm of Fibervisions™ AL-Adhesion. Thesecond forming head added a mixture of 32.3 gsm of FOLEY FLUFFS® pulpand 7.30 gsm of Trevira 1663 bicomponent fibers. Immediately after this,the web was compacted with a compaction roll. 1.20 gsm AIRFLEX® 192latex emulsion was then sprayed onto the top of the web. The web wasthen cured in a Moldow Through Air Tunnel Dryer at a temperature of 135°C. After this, the web was wound in a roll. The machine speed wasapproximately 10-20 meters/minute.

Example 3 Padformed Samples of Allergen Barrier Material

Basic padformed structures A, B, and C, see Table 1, formed in Example 1were each trimmed to 0.3556 meters by 0.3556 meters (14 inch by 14 inch)samples. One surface of each of substrates A and B was sprayed with awater-based adhesive available as 3M Fastbond™ Insulation Adhesive 49produced by 3M, and the product was cured in a laboratory oven at 150°C. for 15-20 minutes.

3M Fastbond™ Insulation Adhesive 49 is an aqueous dispersion of anacrylate polymer, with a solids content of 53-57 percent and a pH of4.1-4.5, and which is non-flammable in the wet state. Against a glasssubstrate the 180 peel strength is 2.8 N/10 mm and the overlap shear is0.37 Mpa.

The basis weights of Samples A and B with the adhesive add-on were 50gsm. Sample C formed in Example 1 to a 50.0 gsm basis weight served asthe control for this experiment. The samples were sticky to the touch.Table 3 below shows the amount of adhesive add-on to each substrate.

TABLE 3 Composition of 50.0 gsm Padformed Samples Substrate Add-onAmount of 3M Experimental Basis Weight Fastbond ™ Insulation TotalPadformed Substrate (gsm) Adhesive (gsm) (gsm) A 40.0 10.0 50.0 (A2) B45.0 5.0 50.0 (B2) C 50.0 0 50.0 (C2)

Samples D and E of the basic padformed structures formed in Example 1,see Table 1, were each trimmed to 0.3556 meters by 0.3556 meters (14inch by 14 inch). One surface of substrate D was sprayed with awater-based adhesive available as 3M Fastbone™ Insulation Adhesiveproduced by 3M, and the product cured in a laboratory oven at 150° C.for 15-20 minutes to produce D-1. The procedure was repeated using anacrylic vinyl acetate copolymer available as DUR-O-SET® manufactured byVinamul® as the spray-on adhesive emulsion to produce D-2, and a verysoft acrylic binder available as FLEXCRYL® 1625 produced by Air Productsas the spray-on adhesive emulsion to produce D-3. The basis weight ofSamples D-1, D-2 and D-3 after adhesive add-on was 100 gsm. Sample Efrom Example 1 with a 100.0 gsm basis weight served as the control forthis experiment. The samples were sticky to the touch. DUR-O-SET® is ahigh-solids, surfactant stabilized ethylene-vinyl acetate terpolymeremulsion with a pH of 4.5-5.5 and a solids content of 55-60 percent.

FLEXCRYL® 1625 is a high-solids water-based vinyl acrylate pressuresensitive adhesive with a solids content of about 68 percent, a pH ofabout 5, a Tg of about −48° C. It is sold as a carboxylated acrylicemulsion and manufactured by Air Products.

Table 4 below shows the type and amount of adhesive add-on to eachsubstrate.

TABLE 4 Composition of 100.0 gsm Padformed Samples ExperimentalPadformed Substrate D-1 D-2 D-3 E Substrate Basis Weight (gsm) 80.0 80.080.0 100.0 Adhesive 3M Fastbond ™ 20.0 0 0 0 DUR-O-SET ® 0 20.0 0 0FLEXCRYL ® 0 0 20.0 0 1625 Total (gsm) 100.0 100.0 100.0 100.0

FIG. 2 presents a photograph of padformed sample D-3 taken at amagnification of 150×. Unless otherwise indicated, this and all otherimages presented herein were taken in-house using a HITACHI® S-3500NScanning Electron Microscope.

Example 4 Dust Capture Performance

The performance of the five padformed barrier substrates and the twocontrols was tested to explore their dust capturing capacities. Thematerial used was a silica-based material available as Arizona Test Dust(A.T.D.), manufactured by Powder Technology, which is used to testfilters and has particles that range in size from 0.807-μm to 78.16-μm.

0.2032 meter (8-inch) diameter circles from each of the test sampleswere cut and were each positioned with adhesive side down on an ASTM No.30 (600-μm) sieve of a RO-TAP® Testing Sieve Shaker Model B. A bottompan was placed below the No. 30 screen.

Approximately 0.5-grams of A.T.D. was deposited in the center of thenon-adhesive surface of the test substrate and the dust then permittedto permeate through the sample by RO-TAP® oscillations for a duration of30 minutes. The RO-TAP® instrument has 278 uniform oscillations perminute and 150 taps per minute as specified by ASTM standards.

Complete instructions and procedures on the use and calibration oftesting sieves are contained in ASTM STP447B. Note that in standardRO-TAP® applications, sieve analysis results from two testing sieves ofthe same sieve designation may not be the same because of the variancesin sieve opening permitted by this specification. To minimize thedifferences in sieve analysis results, the use of testing sieves matchedon a performance basis is suggested. ASTM STP447B also contains a listof all published ASTM standards on sieve analysis procedures forspecific materials or industries. This list may be referenced to obtainstatements of precision and bias for sieve analysis of specificmaterials. Since the RO-TAP® Testing Sieve Shaker was used, in the caseof this experiment, for its agitation capabilities (which permitted asubsequent measurement of the dust holding capacity of the testsubstrates), and not for classification of particle sizes, minorvariations in mesh size of testing sieves used should not make adifference.

The percent of A.T.D. that remained associated with the substrates afteroscillation was then calculated. Table 5 below summarizes theperformance results.

TABLE 5 Summary of Dust Capturing Capacity of 50-gsm and 100-gsmPadformed Barrier Substrates Sample A2 B2 C2 D-1 D-2 D-3 E % Dust heldby 68.2% 47.8% 5.61% 72.4% 82.6% 86.9% 45.1% Pad after RO- TAP ®Oscillation

The RO-TAP® laboratory tests suggest that Sample D-3, the 100-gsm padwith FLEXCRYL® 1625, has the best dust holding capacity of thesubstrates tested.

FIG. 3 shows a scanning electron micrograph of the padformed sample D-3.Arizona Test Dust retained after a Dust Capture Performance Test isvisible. The image is at a magnification of 150×.

Example 5 Pilot Samples of Allergen Barrier Material

A sample of the basic NTL3 nonwoven product prepared in Example 2, seeTable 2, was sprayed on one surface with a very soft acrylic adhesive,FLEXCRYL® 1625 produced by Air Products, and air-dried for severalhours. A sample of NTL3 without adhesive add-on served as the controlfor this portion of the experiment. Table 6 below shows the amount ofadhesive add-on to the substrates.

TABLE 6 Composition of NTL3 Pilot Samples Substrate Add-on Amount ofBasis Weight Flexcryl ® 1625 Total Experimental Sample (gsm) Adhesive(gsm) (gsm) NTL3 Substrate 1 69.9 20.0 89.9 NTL3 Control 69.9 0 69.9

FIG. 4 is a micrograph of a cross-section of the Pilot Plant sample ofNTL3, Substrate 1 coated with the Flexcryl 1625 adhesive. The image ismagnified at 90×. The micrograph of FIG. 4 shows the low density natureof the barrier fabric as well as the penetration of the adhesive throughthe top half of the material.

The performance of the pilot samples was tested in multiple ways.

Phase 1. The first phase of testing of the prepared substrates sought toexplore the dust-trapping capacity of the nonwoven NTL3 Substrate 1. Thematerial used, as in the case of the padformed samples, was asilica-based dust, Arizona Test Dust (A.T.D.), manufactured by PowderTechnology. The procedure described in Example 4 using the RO-TAP® SieveShaker was used to analyze the pilot samples.

Table 7 summarizes the performance results from Phase 1.

TABLE 7 Summary of Dust Capturing Capacity of Pilot Substrate SampleNTL3 Substrate 1 NTL3 Control % Dust held by Substrate after RO- 88.8%21.63% TAP ® Oscillation

The closer the values are to 100 percent, the higher is the measuredefficiency of the nonwoven material as a filter and a sticky trap thatis able to capture and hold microscopic dust-like particles.Potentially, NTL3 Substrate 1 could have a filtering efficiencyapproaching 100% if the A. T. D. is applied as an even dispersion, andis not deposited in its entirety at the center of the substrate, wherethere is a propensity to overload the holding capacity of the materialat the center.

Phase 2. The second phase of testing involved cutting 0.6096-meter by0.6096-meter (2-feet by 2-feet) squares of NTL3 Substrate 1 and applyingit, adhesive side down, to a mattress with only a sheet over it and to apillow inside of a pillowcase that were in consistent use. The nonwovenmaterial remained adhered to the mattress and pillow for a duration of25 days and were subject to the normal wear and tear and pressurebrought about by the occupants of the bed. The nonwoven barriersremained intact at the end of this period, indicating that it was ofsufficient basis weight and durability to be able to withstand use whileadhered to mattress and pillow in regular use. FIG. 5 is an image of thematerial after the 25 day test.

FIG. 6 presents another micrograph taken after 25 days of use. Themicrograph was taken at a magnification of 150× (WD=26.1 mm, kV=15). Themicrograph shows that the NTL3 layer is intact and has trapped manyparticles during the 25 day period.

FIGS. 7 and 8 present additional micrographs taken after 25 days of use.The micrographs were taken at increased magnifications of 400× and 800×,respectively. Entrapped particles are more clearly seen.

Phase 3. The next phase of testing NTL3 Substrate 1 occurred under thesupervision of entomologist and acorologist Dr. Glen R. Needham, Ph.D.Dr. Needham is on faculty at The Ohio State University (OSU) in theDepartment of Entomology. The University test facility is located inColumbus, Ohio. Phase 3 testing is described in detail in Example 6.

Example 6 Dust Mite Trapping

Samples of NTL3 Substrate 1 were shipped to OSU for a preliminary TrapTest that would examine dust mite adherence and movement. The experimentinvolved cutting small circles of NTL3 Substrate 1 and of mattressticking material to fit the bottom of a glass Petri dish. The mattressticking was first placed at the bottom of the dish. Approximately 20live mites from a culture were placed on the FLEXCRYL® 1625 side of theNTL3 Substrate 1 disc. This sample was then inverted and placed on themattress ticking in the Petri dish. It was held next to the ticking by afine steel wire mesh placed on top of the NTL3 Substrate 1 sample. Thesides of the Petri dish were lined with petroleum jelly to keep themites from crawling out of the dish. The experiment was allowed toproceed overnight. The following day, it was observed that the mitesplaced on the adhesive surface of NTL3 Substrate 1 showed evidence ofmovement of their extremities, indicating that they were still alive,but there was considerable impediment to locomotion due to the trappingability and adhesive drag of the FLEXCRYL® 1625 adhesive.

Mite appearance and behavior on NTL3 Substrate 1 was recorded in realtime using a video camera as shown in FIG. 9. See FIG. 9 for a stillimage from Dr. Needham's video clip showing all but two dust mites(circled) immobilized by the NTL3 adhesive barrier.

The experiment was repeated using a commercially available syntheticnonwoven mattress barrier for comparison to NTL3 Substrate 1. At the endof the experiment, it was observed that, in this case, the mites werefreely moving about, unaffected by the barrier layer. FIG. 10 presents astill image from a video showing all of the dust mites moving freely ona known mattress encasement product.

It was concluded that NTL3 Substrate 1 functioned very effectively as atrap for dust mites as all but two mites were trapped within theadhesive of the sample and incapacitated as a result, as indicated inFIG. 9.

FIG. 11 presents a micrograph showing a dust mite and dust mite larvahaving been trapped by the NTL3 Substrate 1 barrier material. This,again, was in conjunction with Dr. Glen Needham's experiment at The OhioState University. The image is magnified 200× to more clearly showfeatures of the dust mite. It is noted that the mite appears flatbecause the sample was dessicated in a drying oven to preserve thesample. FIG. 12 presents another micrograph showing a dust mite trappedby the NTL3 Substrate 1 barrier material. The image is magnified 180× tomore clearly show features of the dust mite. It can be seen that thedust mite was initially captured by the adhesive. The mite molted,moved, and then was recaptured by the barrier fabric.

Example 7 Clinical Testing

Barrier samples obtained from Example 6 were sent for testing to MTReference Laboratory located in Lenexa, Kans., a national research andspecialty clinical lab that provides a wide range of tests and servicesin the area of allergy, clinical immunology and molecular biology.Buckeye's NTL3 Substrate 1 was tested for specific allergen barrierproperties using a modified Fussnecker filtration apparatus. Thisapparatus is based on the design reported by Vaughn, J W et al (JACI1999; 103: 227-231). The procedure involved calibrating airflowmeasurements through the NTL3 Substrate 1 against a fabric control witha known airflow rate. Next, 500-mg of a dust sample containing knownamounts of feline Fel d1 and dust mite Der f1 allergens were pulledacross each fabric. A filter cassette mounted downstream from the fabriccollected any allergen that was able to penetrate the fabric. The filterwas then extracted in 2.0 mL of 1% bovine serum albumin (BSA) inphosphate buffered saline (PBS)-Tween 20 overnight. The extract wasassayed the following day with an Enzyme-Linked Immunosorbent Assay(ELISA) for the relevant allergen. The detection limits of the airflowtest for the Fel d1 allergen and the Der f1 allergen are 0.31 ng and 1.3ng respectively. If results fall below the detection limits of the test,it can be concluded that the fabric being tested is an effective barrierto Fel d1 and Der f1 allergen transfer. The Allergen Barrier Test wasperformed on a sample of NTL3 Substrate 1, as well as on a high porositybarrier fabric labeled “High Fabric Control” and on a low porositybarrier fabric labeled “Low Fabric Control.” Table 8 below summarizesresults obtained from IBT Reference Laboratory on the Allergen BarrierTest.

TABLE 8 Results of Allergen Barrier Test with Airflow Device on NLT3Substrate 1 Sample Airflow through Fabric Fel d1 Der f1 Identification(L/min) (ng) (ng) NLT3 Substrate 1 33.7 34.6 <1.3 High Fabric Control34.4 2483.7 190.2 Low Fabric Control 18.6 <0.31 <1.3 Dosed Dust ControlNA 61623 478

Allergen Barrier Test data from IBT show the following. The NTL3Substrate 1 experimental barrier was almost as porous as the highporosity High Fabric Control, permitting a substantial volume of airflowthrough the fabric. The NTL3 Substrate 1 barrier had almost twice theairflow of the low porosity Low Fabric Control. When compared to theHigh Fabric Control with the similar porosity, the NTL3 Substrate 1decreased the Fel d1 feline allergen by 99% and reduced the Der f1 dustmite allergen to below detectable limits. The NTL3 Substrate 1 had theairflow of a high porosity fabric, while it performed almost aseffectively as a low porosity fabric in blocking feline and dust miteallergens.

Example 8 Other Adhesives

A sample of the basic airlaid structure, NTL3 formed in Example 2 (Table2) was sprayed on one surface with a 9.77% aqueous solution of NACOR®38-088A, produced by Natural Starch, and air-dried for several hours toproduce NLT3-15 to produce an effective add-on of 14.5 gsm. Another NLT3sample was sprayed with a 15% aqueous solution of NACOR® 38-088A toproduce NLT3-30 an effective add-on of 29.5 gsm.

NACOR® 38-088A is an aqueous emulsion of an acrylic copolymer with asolids content of 52 percent and a pH of 7.0 with a 180 24 hour peelfrom stainless steel of 70 oz/in and a shear at 22 C of 8 hours at 4 psiand a tack of 32 oz/in². NACOR is available from National Starch andChemical Co. of Bridgewater, N.J.

Table 9 below shows the amount of adhesive add-on to each of the twosubstrates. Note that although the substrate used was the same one asthe basic airlaid NLT3 formed in Example 2, formation irregularities inairfelts causes the basis weight to differ slightly from area to area.

TABLE 9 Composition of NTL3 Control with NACOR ® 38-088A SubstrateAdd-on Amount of Basis Weight NACOR ® 38-088A Total Experimental Sample(gsm) Adhesive (gsm) (gsm) NTL3-15 62.1 14.5 76.6 NTL3-30 65.4 29.5 94.9

NLT3-15 and NLT3-30 barrier samples were tested by IBT ReferenceLaboratory using the procedure described above. Table 10 belowsummarizes results obtained from IBT Reference Laboratory on theAllergen Barrier Test.

TABLE 10 Results of Allergen Barrier Test with Airflow Device on NLT3-15and NLT3-30 Sample Airflow through Fabric Fel d1 Der f1 Identification(L/min) (ng) (ng) NLT3-15 35.4 57.5 <1.3 NLT3-30 35.5 26.7 <1.3 HighFabric Control 35.7 2381.6 161.3 Low Fabric Control 18.8 <0.31 <1.3Dosed Dust Control NA 61623 478

The Allergen Barrier Test data from MT show the following. The NTL3-15and NLT3-30 experimental barrier substrates were virtually as porous asthe high porosity High Fabric Control, permitting a substantial volumeof air through the fabric. The NTL3-15 and NLT3-30 experimental barriersubstrates had almost twice the airflow of the low porosity Low FabricControl. When compared to the High Fabric Control with the similarporosity, the NTL3-15 substrate decreased the Fel d1 feline allergen by98% and reduced the Der f1 dust mite allergen to below detectablelimits. When compared to the High Fabric Control with the similarporosity, the NTL3-30 substrate decreased the Fel d1 feline allergen by99% and reduced the Der f1 dust mite allergen to below detectablelimits. The NTL3-15 and NTL3-30 substrates had the airflow of a highporosity fabric, while they performed almost as effectively as a lowporosity fabric in blocking feline and dust mite allergens.

NLT3-15 and NLT3-30 with FDA-approved NACOR® 38-088A were as effectiveas NLT3 Substrate 1 with FLEXCRYL® 1625 in blocking and trapping felineand dust mite allergens. Based on the similarity in effective functionof the NLT3-15 and NLT3-30 barriers, it was concluded that a NACOR®38-088A add-on of 20.0 gsm to NLT3 would be adequate for routine use asa dust mite barrier and trap on mattresses and pillows and in airfilters.

Example 9 Filter Substrate for Active Particulate

A sample of the basic airlaid structure NLT3 formed in Example 1 wastrimmed to 0.0508-m by 0.0508-m (2 inches by 2 inches). It was thensprayed on one surface with a very soft acrylic binder, available asFLEXCRYL® 1625 produced by Air Products, and air-dried for severalhours. Granular Activated Carbon available from Sigma Chemical Companywas ground with a mortar and pestle. It was sieved using a U.S.AStandard Test Sieve No. 200. The fine carbon powder was then applied tothe prepared NLT3-FLEXCRYL® 1625 substrate. Any fine carbon that wasunattached to the substrate was removed with compressed air, leaving thesubstrate with only non-removable activated carbon. The effective add-onof non-removable activated carbon was 19.78% of the total weight of theproduct, referred to as NLT3-Carbon.

Table 11 below shows the composition of the product.

TABLE 11 Composition of NTL3-Carbon NLT3 Add-on Substrate Add-on AmountAmount Experimental Basis Weight of FLEXCRYL ® of Activated Total Sample(gsm) 1625 (gsm) Carbon (gsm) NTL3-Carbon 69.9 20.0 43.0 132.9

NTL3-Carbon could be used as an active filter. Activated carbon is acharcoal that is treated with oxygen in order to open up millions oftiny pores between the carbon atoms, resulting, in a highly adsorbentmaterial. Also, this type of substrate may be used to support any typesof particles which adhere to the adhesive, enabling the customization ofthe filter media.

FIGS. 13 and 14 present micrographs showing the filter media havingcaptured activated carbon. The micrographs were taken at magnificationsof 60× and 250×, respectively. Carbon particles are even more clearlyseen. The activated carbon particles will aid in trapping odors andchemicals.

Example 10 Filtration Media Substrate

Three airlaid substrates designated AFM-1, AFM-2, and AFM-3 wereprepared on a DannWebb pilot scale airlaid manufacturing unit at BuckeyeTechnologies, Inc., Memphis, Tenn. The raw materials in all threesubstrates consisted of a southern softwood Kraft fluff pulp, availableas FOLEY FLUFFS® from Buckeye Technologies Inc., Memphis, Tenn.,bicomponent binder fiber with a polyethylene sheath over a polyestercore available as Type T-255 with merge number 1663, made by TreviraGmbH of Bobingen, Fibervision™ AL 4-Adhesion bicomponent fibers producedby Fibervisions, an ethyl vinyl acetate latex binder available asAIRFLEX® 192 manufactured by Air Products and an acrylic waterbornepressure sensitive adhesive available as NACOR® 38-088A, manufactured bythe Adhesives Division of National Starch & Chemical Company. Trevira'sT-255 Merge No. 1663 bicomponent fiber has a denier of 2.2-dtex, and is0.003-meter (3-mm) in length, with a 50/50 ratio of polyester topolyethylene. Fibervision™ AL 4-Adhesion bicomponent fibers consist of apolypropylene core and a polyethylene sheath. The produced airlaidstructures, AFM-1, AFM-2 and AFM-3, had total basis weights of 106.5gsm, 106.5 gsm, and 113.5 gsm respectively.

The pilot substrate AFM-1 was prepared according to the compositiongiven in Table 12 on the pilot line.

TABLE 12 Composition of AFM-1 Component of Substrate Gsm SouthernSoftwood Pulp - FOLEY FLUFFS ® 40.0 Bicomponent Fiber (PET/PE) - Trevira1663 9.0 Fibervision ™ AL-Adhesion Fiber 36.0 EVA Latex Binder Spray -AIRFLEX ® 192 1.5 Pressure Sensitive Adhesive - NACOR ® 38-088A 20.0 at15.0% solids content Total Basis Weight (gsm) 106.5

The pilot substrate AFM-2 was prepared according to the compositiongiven in Table 13 on the pilot line.

TABLE 13 Composition of AFM-2 Component of Substrate Gsm SouthernSoftwood Pulp - FOLEY FLUFFS ® 40.0 Bicomponent Fiber (PET/PE) - Trevira1663 9.0 Fibervision ™ AL-Adhesion Fiber 36.0 EVA Latex Binder Spray -AIRFLEX ® 192 1.5 Pressure Sensitive Adhesive - NACOR ® 38-088A 0.0 at10.0% solids content Total Basis Weight (gsm) 106.5

AFM-1 and AFM-2 were prepared individually in three layers. The firstforming head added a mixture of 40.0 gsm of FOLEY FLUFFS® pulp and 9.0gsm of Trevira 1663 bicomponent fibers. The second forming head added36.0 gsm of Fibervision™ AL 4-Adhesion. Immediately after this, the webwas compacted via the compaction roll at 4.3 bars. Then, 20.0 gsm NACOR®38-088A pressure-sensitive adhesive at 15.0% mixture solids content(AFM-1), or at 10.0% mixture solids content (AFM-2) was sprayed onto thetop of the web. The web was cured in a Moldow Through Air Tunnel Dryerat a temperature of 140° C. After this, the web from each condition waswound as a 20-inch diameter roll. The roll was then unwound and run backthrough the pilot line and 1.5 gsm AIRFLEX®-192 latex emulsion wasapplied onto the reverse side of the web. The machine speed was 15meters/minute.

The substrate, AFM-3, was also prepared on a DannWebb pilot scaleairlaid manufacturing unit at Buckeye Technologies, Inc., Memphis, Tenn.This substrate was identical in manufacture and composition to AFM-1 andAFM-2, with the exception of the gsm add-on of the pressure sensitiveadhesive, NACOR® 38-088A.

The pilot substrate AFM-3 was prepared according to the compositiongiven in Table 14 on the pilot line.

TABLE 14 Composition of AFM-3 Component of Substrate Gsm SouthernSoftwood Pulp - FOLEY FLUFFS ® 40.0 Bicomponent Fiber (PET/PE) - Trevira1663 9.0 Fibervision ™ AL-Adhesion Fiber 36.0 EVA Latex Binder Spray -AIRFLEX ® 192 1.5 Pressure Sensitive Adhesive - NACOR ® 38-088 27.0 at20.0% solids content Total Basis Weight (gsm) 113.5

The filtration efficiency performance of the 3 substrates prepared atthe pilot plant was tested off-site at Blue Heaven Technologies, locatedin Louisville, Ky.

The experiment performed at Blue Heaven involved cutting the 3substrates (AFM-1, AFM-2, and AFM-3) to a size of 24-inches by24-inches, affixing them each to a 24-inch by 24-inch by 1-inch frame(FIG. 15), and sealing it in an ASHRAE (American Society of Heating,Refrigerating and Air-Conditioning Engineers) standard 52.2-1999 testduct. ASHRAE Standard 52.2-1999 entitled “Method of Testing GeneralVentilation Air Cleaning Devices for Removal by Particle Size” is astandardized laboratory test method and HVAC industry standard formeasuring the filtration efficiency of ventilation air filters used inresidential and commercial buildings. The substrates, AFM-1, AFM-2, andAFM-3, were oriented in the test duct in such a way that the side withthe Fibervision™ AL 4-Adhesion bicomponent fibers layer faced upstream.

The airflow in the ASHRAE standard 52.2-1999 test duct was then set at aconstant value of 472 cfm. A test aerosol was injected upstream of thesubstrates while a particle counter was used to count the number ofparticles upstream and downstream of the substrates in 12 size rangesfrom 0.3-10 μm diameter. This particular size range is chosen in orderto test a filter's ability to filter respirable size particles. Theratio of the downstream counts to the upstream counts was used tocompute the filtration efficiency of AFM-1, AFM-2, and AFM-3 for each ofthe 12 size ranges. Based on the minimum filtration efficienciesobserved during the test of the substrates, the analyst at Blue HeavenTechnologies was able to assign each of the substrates a MERV value asdefined by the ASHRAE Standard 52.2 test method. MERV is the “MinimumEfficiency Reporting Value” for a filter. It is assigned to a substratedepending on its particle filtering efficiency (PSE) in three differentparticle size ranges (0.3 to one micrometer, one to three micrometers,and three to 10 micrometers). The MERV value is an indication of theminimum efficiency that can be expected from that particular filtersubstrate, and is an excellent representation of filter performance.This number is also intended to help people compare filters.

Table 15 below summarizes results obtained from Blue Heaven Technologieson the three filter substrates, AFM-1, AFM-2, and AFM-3.

TABLE 15 ASHRAE 52.2 Test Data on AFM-1, AFM-2, and AFM-3 FiltrationPilot Plant Substrate AFM-1 AFM-2 AFM-3 Airflow Rate (CFM) 472 472 472Nominal Face Velocity (fpm) 118 118 118 Initial Resistance (in WG) 0.100.12 0.10 E1 (%) Initial Efficiency 1 2 1 0.30-1.0-um E2 (%) InitialEfficiency 27 35 28 1.0-3.0-um E3 (%) Initial Efficiency 66 73 653.0-10.0-um Estimated Minimum MERV 7 @ MERV 8 @ MERV 7@ EfficiencyReporting 472 CFM 472 CFM 472 CFM Value (MERV)

Based on the ASHRAE Standard 52.2 test results, the followingconclusions were made.

The substrate AFM-2 had the highest percent filtration efficiency in allof the three different particle size ranges (0.3 to one micrometer, oneto three micrometers, and three to 10 micrometers).

Consequently, at a MERV 8 at an airflow rate of 472 CFM, Substrate AFM-2exhibited the best filter performance of the three substrates.

Based on the data, it is evident that the differences in the formulationand quantity of application of the solution of NACOR® 38-088A, thepressure sensitive adhesive used in the preparation of substrates AFM-1,AFM-2, and AFM-3, resulted in a difference in filtration efficiency asrepresented by the MER value.

Based on the data generated from substrate AFM-2 led to a secondaryexperiment at Blue Heaven Technologies. The procedure in this caseinvolved generating a fourth substrate by placing two samples of thesubstrate AFM-2 together in the same orientation. This substrate willhenceforth be referred to as AFM-2X2. The substrate AFM-2X2 had thecomposition listed in Table 16.

TABLE 16 Composition of AFM-2X2 Component of Substrate Gsm SouthernSoftwood Pulp - FOLEY FLUFFS ® 80.0 Bicomponent Fiber (PET/PE) - Trevira1663 18.0 Fibervision ™ AL-Adhesion Fiber 72.0 EVA Latex Binder Spray -AIRFLEX ® 192 3.0 Pressure Sensitive Adhesive - NACOR ® 38-088A 40.0 at10.0% solids content Total Basis Weight (gsm) 213.0

AFM-2X2 was then subjected to the identical ASHRAE Standard 52.2-1999test as the previous substrates. As before, the substrate was orientedin the test duct in such a way that the side with the top layer ofFibervision™ AL 4-Adhesion bicomponent fibers faced upstream.

Table 17 below summarizes results obtained from Blue Heaven Technologieson the filter substrate, AFM-2X2.

TABLE 17 ASHRAE 52.2 Test Data on AFM-2X2 Airflow Rate (CFM) 472 NominalFace Velocity (fpm) 118 Initial Resistance (in WG) 0.23 E1 (%) InitialEfficiency 0.30-1.0-um 6 E2 (%) Initial Efficiency 1.0-3.0-um 54 E3 (%)Initial Efficiency 3.0-10.0-um 91 Estimated Minimum Efficiency ReportingMERV 10 @ 472 CFM Value (MERV)

Table 18 below summarizes the data for initial resistance obtained fromBlue Heaven Technologies for each of the substrates tested. Graphicalrepresentations of the data are provided in FIGS. 18A-D.

TABLE 18 Airflow (CFM) AFM1 AFM2 AFM3 AFM2X2 0 0.00 0.00 0.00 0.00 1180.02 0.03 0.02 0.05 236 0.04 0.06 0.04 0.10 354 0.07 0.09 0.07 0.16 4720.10 0.12 0.10 0.23 590 0.13 0.16 0.13 0.30

Table 19 below summarizes the data for particle removal efficiencyobtained from Blue Heaven Technologies for each of the substratestested. Graphical representations of the data are provided in FIGS.19A-D.

TABLE 19 Initial Particle Initial Particle Initial Particle InitialParticle Removal Removal Removal Removal Particle Size Geometric MeanEfficiency (%) Efficiency (%) Efficiency (%) Efficiency (%) Range (um)Diam. (um) AFM1 AFM2 AFM3 AFM2X2 0.30-0.40 0.35 0.0 0.0 0.0 0.00.40-0.55 0.47 0.0 0.0 0.0 0.0 0.55-0.70 0.62 0.0 0.0 0.2 7.1 0.70-1.000.84 2.3 6.1 3.7 18.1 1.00-1.30 1.14 15.1 20.4 16.2 36.4 1.30-1.60 1.4421.7 28.8 22.3 45.8 1.60-2.20 1.88 28.6 37.3 29.0 57.7 2.20-3.00 2.5743.3 53.4 42.9 74.8 3.00-4.00 3.46 58.6 66.9 57.1 87.3 4.00-5.50 4.6965.7 73.0 63.5 91.4 5.50-7.00 6.20 70.7 75.8 66.8 92.3  7.00-10.00 8.3769.6 76.7 70.8 93.1

Based on the ASHRAE Standard 52.2 test results on AFM-2X2, the followingconclusions were derived.

An increase in basis weight of the substrate resulted in a significantimprovement in filtration efficiency as represented by the MER value.

For a MERV 10 @ 472 CFM filter, the relatively low initial resistance asexpressed in units of Water Gauge may indicate good porosity and,possibly, better energy efficiency associated with operating an airfiltration system with substrate AFM-2X2.

Previous analysis on a similar substrate, NLT3 from Example 2, involvedvisually examining the dust-capturing characteristics of the pilot plantsubstrate using the Hitachi S3500-N Variable Pressure Scanning ElectronMicroscope on-site. Prior to examination, the substrate had been dosedwith imitation dust, a silica-based material available as Arizona TestDust (A.T.D.), manufactured by Powder Technology. This dust is normallyused to test filters and has particles that range in size from 0.807-μmto 78.16-μm. The dust-dosed substrate was then sputter-coated with goldusing the EMITECH K550x Sputter Coater. Secondary electron images (FIGS.16 and 17) were captured at an accelerating voltage of 15.0 kV at aworking distance of 10-mm.

Based on visual examination, it was concluded at the time that thedust-capturing capacity of the substrate NTL-3 was greater than thatpredicted merely from the apparent surface area of the fibers comprisingthe media. The waterborne pressure-sensitive adhesive, FLEXCRYL® 1625,coating the fibers of the NTL3 media appeared to have a re-wettingcapability, making it possible to capture a dust particle, and then wetand incorporate that particle into the adhesive. This resulted in thatarea of the adhesive-coated fiber becoming available again for dustcapture.

It was also noted during visual analysis of NTL3 from Example 2, andAFM-1, AFM-2, and AFM-3, that the waterborne pressure-sensitiveadhesives, FLEXCRYL® 1625 and the NACOR® 38-088A, that had been sprayedon the web during manufacture of the substrate in the pilot plant, didnot remain entirely on the top surface of the substrate, but hadpenetrated through the pores of the top layer of fibers, settling in thebody of the material. Much of this effect can be attributed to the factthat the top layer of Fibervision™ AL 4-Adhesion bicomponent fibers,consisting of a polypropylene core and a polyethylene sheath, ishydrophobic, causing the waterborne adhesive to selectively migrate tothe more hydrophilic wood fiber layer underneath. This made it possibleto wind the web into a roll in the pilot plant and efficiently unrollit, as the top surface did not exhibit significant tack.

Example 11 Non-Limiting Example of Tacky Material with Multiple Layers

FIG. 1 presents a perspective view of a tacky material 100, in oneembodiment. In this arrangement, a multi-strata substrate is employed.

First, a top layer 10 is provided. The top layer 10 represents anonwoven, airlaid fiber matrix. This layer 10 is not treated with anyadhesive or miticide, and is fabricated or made from a soft, cottonlinter in order to serve as a sleeping surface. The top strata 10includes an upper surface on which a user may place a fitted sheet andthen lay.

Second, the tacky material 100 includes an upper intermediate nonwovenmaterial layer 20. This upper intermediate stratum 20 has a top surface22 and a bottom surface 24. The upper intermediate layer 20 isimpregnated with an aggressively tacky adhesive for trapping dust mitesand other allergens moving into and out of a mattress (not shown).

Third, the tacky material 100 includes a lower intermediate nonwovenmaterial layer 30. This lower intermediate stratum 30 has a top surface32 and a bottom surface 34. The lower intermediate layer 30 isimpregnated with a mildly tacky adhesive, and then lightly treated witha nontoxic miticide.

Fourth, the tacky material 100 includes a release liner 40. The liner 40defines a thin poly-olefin film which engages the bottom surface 34 ofthe lower intermediate layer 30. The film 40 is releasable and isremoved before the user places the tacky material 100 onto a mattress(or other allergen-bearing article). The film 40 permits multiple tackymaterial units 100 to be vertically stacked, and then packaged forshipment or sale.

The strata 10, 20, 30 preferably include a binder which permits thestrata to be melded together in an oven. Alternatively, or in addition,the strata 10, 20, 30 include a hotmelt adhesive applied to perimetersurfaces for sealing the edges.

A light-weight container 50 is provided for packaging. The light-weightcontainer may be a transparent polyethylene sleeve or plastic bag thatis labeled for retail sale. Alternatively, it may be a cardboard box.Alternatively still, the container 50 may be a more durable andstackable poly-carbonate container as shown in FIG. 1. Other containersmay be employed, and the tacky material 100 is not limited in scope tothe method of packaging or shipping. The container 50 includes awater-tight interior 52 for receiving the tacky material 100. Aremovable sealing member 58 is applied along an upper lip 56 of thecontainer 50 to seal the container 50.

Preferably, the container 50 is smaller in area than the tacky material100. The tacky material 100 is folded over one or more times beforebeing inserted into the container 50. This permits multiple tackymaterial units 100 to fit more readily into the container 50.

It is understood that the tacky material 100 of FIG. 1 is merelyexemplary; other arrangements and materials consistent with thisdisclosure may be employed. FIG. 1 is intended to present variousfeatures and options together that might more preferably be independentfeatures. For instance, the tacky material might only have a singlelayer that has a mildly tacky adhesive sprayed onto one exteriorsurface. The material may be rolled or folded and then inserted into asleeve for transport. The tacky material might then be carried through aconverting process to place it in retail form.

All patents, patent applications, publications, product descriptions andprotocols, cited in this specification are hereby incorporated byreference in their entirety. In case of a conflict in terminology, thepresent disclosure controls.

While it will be apparent that the invention herein described is wellcalculated to achieve the benefits and advantages set forth above, thepresent invention is not to be limited in scope by the specificembodiments described herein. It will be appreciated that the inventionis susceptible to modification, variation and change without departingfrom the spirit thereof. For instance, the nonwoven structure isdescribed in the context of an airlaid process. However, non-airlaidprocesses are also contemplated.

What is claimed is:
 1. An airlaid unitary multistrata material,comprising: a woven or nonwoven multistrata substrate containing: a tophydrophobic stratum comprising synthetic fibers and, optionally, abinder; (ii) an intermediate stratum comprising cellulose fibers,synthetic fibers, and tacky adhesive, wherein the tacky adhesive ispresent in an amount from about 20 gsm to about 300 gsm; and (iii) abottom stratum comprising cellulose fibers, synthetic fibers and,optionally, a binder; wherein the intermediate stratum is impregnatedwith the tacky adhesive and the tacky adhesive is coextensivelycontiguous with a surface of at least one stratum; wherein the substratehas a density of from about 0.035 g/cm³ to about 0.10 g/cm³; wherein thecaliper of the substrate is from about 3 mm to about 60 mm, wherein theairflow resistance of the substrate is 500-10,000 Rayls (Ns/m³); andwherein the multistrata substrate is an airlaid material.
 2. The unitarymultistrata material of claim 1, wherein the substrate further comprisesa scrim being of a spunbond material, a meltblown material, a wetlaid orairlaid nonwoven material, a textile, a woven or nonwoven syntheticmaterial.
 3. The unitary multistrata material of claim 1, wherein thestrata of the multistrata substrate are melded together by heat.
 4. Theunitary multistrata material of claim 1, wherein the substrate has abasis weight of from about 35 gsm to about 500 gsm.
 5. The unitarymultistrata material of claim 4, wherein the substrate contains fromabout 30 weight percent to about 95 weight percent fibers and from about5 weight percent to about 70 weight percent of a binder wherein theweight percentages are based on the total weight of the multi stratasubstrate.
 6. The unitary multistrata material of claim 5, wherein thesubstrate contains from about 50 weight percent to about 95 weightpercent fibers and from about 5 weight percent to about 50 weightpercent of a binder.
 7. The unitary multistrata material of claim 1,wherein the binder is a latex or other liquid binder, a bicomponent orother fiber binder, a powdered or pelletized synthetic binder, or acombination thereof.
 8. The unitary multistrata material of claim 1,wherein the tacky material has a basis weight of from about 40 gsm toabout 1300 gsm.
 9. The unitary multistrata material of claim 1, whereinthe tacky adhesive is coextensively contiguous with the one or moreselected areas of the substrate.
 10. The unitary multistrata material ofclaim 1, wherein the tacky adhesive is a pressure sensitive adhesive.11. The unitary multistrata material of claim 10, wherein the pressuresensitive adhesive is an acrylate, a polyurethane, a poly-alpha-olefin,a silicone, or a self-tacky or tackified natural or synthetic rubber.12. The unitary multistrata material of claim 1, formed in the shape ofa polygon with an edge circumference of from about 30 cm to about 15meters.
 13. The unitary multistrata material of claim 12, wherein theedge circumference is from about 1 meter to about 15 meters.
 14. Theunitary multistrata material of claim 12, wherein the edge circumferenceis shaped to cover an upper surface of a mattress.
 15. The unitarymultistrata material of claim 14, wherein the material has four sideswith angles between the sides of about 90°.